Color composite from Hubble Space Telescope, revealing the bow shock caused by stellar wind from LL Orionis.
Color composite from Hubble Space Telescope, revealing the bow shock caused by stellar wind from LL Orionis.

Looking rather like an alien ship entering the atmosphere in a Spielberg-Lucas space spectacular, this composite color image from the Hubble Space Telescope reveals the bow shock caused by the stellar wind of a young star called LL Orionis. What causes this effect? Still in its relatively early years, LL Orionis produces a far more energetic wind than our middle-aged Sun. In this picture, that wind is blowing against the slower-moving flow of the Orion Nebula. Above and to the right of the central image, a fainter star can be seen creating a similar bow shock as it navigates its way through the expanding gases of the nebula.